Emulate motion controls with a mouse (#3122)

* Rework framework to allow for more types of mouse-to-something emulation and hook up gyro to it

* Remove the unnecessary null check now that deltatime is handled differently

* Fix toggle key

* Basic gyro emulation working for two out of the three dimensions

* clang

* Added bindable key to hold for switching from looking to the sides to rolling

* documentation

src/input/input_mouse.h

@@ -8,11 +8,21 @@
 
 namespace Input {
 
-void ToggleMouseEnabled();
+enum MouseMode {
+    Off = 0,
+    Joystick,
+    Gyro,
+};
+
+bool ToggleMouseModeTo(MouseMode m);
 void SetMouseToJoystick(int joystick);
 void SetMouseParams(float mouse_deadzone_offset, float mouse_speed, float mouse_speed_offset);
+void SetMouseGyroRollMode(bool mode);
 
-// Polls the mouse for changes, and simulates joystick movement from it.
+void EmulateJoystick(GameController* controller, u32 interval);
+void EmulateGyro(GameController* controller, u32 interval);
+
+// Polls the mouse for changes
 Uint32 MousePolling(void* param, Uint32 id, Uint32 interval);
 
 } // namespace Input